In one aspect, this invention relates to a plate or panel formed from polymeric composite material. In another aspect, this invention relates to a protective body garment, such as a vest, which is formed from such composite material.
Paint ball guns fire a paint filled gelatin encapsulated projectile which weighs approximately 50 grains (about 3.2 grams) at a velocity of about 300 feet per second (9150 cm/sec). The kinetic energy of the projectile is given by the formula
e=xc2xdmv2,
which, in the just given example, is about 134 (106) ergs, or about 10 foot pounds, which is an energy level approximately the same as that developed by a small game air gun firing a lead pellet. Being shot at close range with a paint ball gun causes bruising and hurts.
Participants in paint ball games therefore generally wear protective gear, including goggles and heavy clothing. However, the heavy clothing does not absorb the paint ball energy very well and is very uncomfortable for summer use, or for use when the participant is vigorously active in the game. Lightweight protective body armor that is effective for absorbing the energy from the projectiles and is well ventilated for comfortable summertime or high activity level use would be very desirable.
Another problem encountered in paint ball games is that the participants sometimes form teams, but because of the protective gear it is sometimes difficult to quickly determine a player""s allegiance. Protective gear which has capability of being easily converted to displaying a team color which can be quickly differentiated from that of another team would be very desirable.
Participants in other sports also have need for protective gear. For example, participants in martial arts such as karate could benefit from a protective vest which provides good impact protection. Soccer players, hockey players, skaters, skate boarders, and motor cross participants, to name but a few, also are at risk of injury to the torso area and have need for a lightweight protective vest.
It is an object of this invention to provide a lightweight armor plate which is effective to prevent bruising or other tissue damage from impacts such as might be generated by paint balls.
It is another object of this invention to provide a protective garment for sports participants, such as paint ball game participants, which contains such plates.
It is another object of this invention to provide a protective garment for sports participants, such as paint ball game participants, which is well ventilated.
It is a further object of this invention to provide such a protective garment which can be easily converted in color, to facilitate team play in games such as paint ball games.
One embodiment of invention provides a laminate especially well suited for sports body armor. The laminates comprise a sandwich structure of polymer foam between tough plastic sheets. The polymer foam is in the form of a sheet of dimensionally stable structural polymer foam and has a first face and a second face. A first tough plastic sheet is adhered to the first face of the sheet of structural foam, and a second tough plastic sheet is adhered to the second face of the sheet of structural polymer foam. The structure is especially well suited for absorbing and spreading the impact from a projectile having a velocity up to at least about 330 fps (100 m/s), as well as providing protection from fists, feet or clubs traveling at lower velocities.
The above described laminate is well suited for use in the construction of user-protective garments, especially for paint ball game use. A particularly preferred garment is a protective vest for a user which comprises a fabric backer configured to cover the user""s torso and a plurality of protective plates fastened to the fabric backer so as to substantially cover the fabric backer. The protective plates each comprise a dimensionally stable structural polymer foam layer sandwiched between two layers of tough plastic film. The plates absorb paint ball or other impacts while the fabric can be colored to identify the user""s team and permits ventilation from underneath the plates to the outside of the garment.